<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .mercury{
            width: 30px;
            height: 30px;
            background: red !important;
            animation: move 1.5s infinite linear;
        }
        @keyframes move {
            from{transform:rotate(0deg);}
            to{transform:rotate(360deg);}
        }
    </style>
</head>
<body>
    <div class="mercury"></div>
</body>
</html>